I'm not a fad diet person- but my fiance started this about a week ago and he's loving it. I was already 90% there since I've been eating the same lunch and dinner as him, so I just thought- what the heck, I'll give it a try. Today is day 1! I handed out the chocolate covered coffee beans I had at my desk and am looking forward to my peanut butter and celery snack.
I don't have much weight I'd like to lose, 5 or 10 lb would be nice, but if I don't lose anything I won't stress either. So we'll see how this works!
For those who don't know- keto is super low carb. when your body doesn't get any carbohydrates (we're talking less than 80 calories a day from carbs) it starts to use up its fat stores. The body can apparently burn about 1,900 calories from fat stores a day. When your body switches to burning fat it goes into ketosis and you start excreting ketones- at which point you know you are in ketosis. You feel weak for a few days when you enter in, but after that, apparently you feel just fine.
So anyways, it is NOT a lifestyle, or a long term diet, but if you have fat to burn, it's a very effective way of doing it.